chore: replace drain with poll for queue for GameThread

Author: pollend

engine/src/main/java/org/terasology/engine/core/GameThread.java

@@ -70,9 +70,10 @@ public static void synch(Runnable process) throws InterruptedException {
      */
     public static void processWaitingProcesses() {
         if (Thread.currentThread() == gameThread) {
-            List<Runnable> processes = Lists.newArrayList();
-            pendingRunnables.drainTo(processes);
-            processes.forEach(Runnable::run);
+            Runnable inst;
+            while((inst =pendingRunnables.poll()) != null) {
+                inst.run();
+            }
         }
     }